The dream sequences in novels or movies or TV shows usually put me to sleep, perchance to dream. They are typically little more than a clumsy way of attaching symbolic resonance to the story, but without advancing plot, characterdevelopment—an awkward Freudian intrusioninto the narrative.

The dream sequences in myths and folktalesare something altogether different. Heredreams are constitutive. They might predictthe future or offer sage advice; they may evencreate the surrounding reality. Recall that inAustralian Aboriginal culture, the time ofcreation is known as “Dreamtime,” and awhole host of beliefs and institutions, bothspiritual and practical, are included under the rubric of “The Dreaming.”

A few writers of conceptual fiction have tried to bridge this gap, imagining a return from our degraded psychoanalytical concept of the dream to the creative, constitutive dreaming of traditional societies. For example, in Jonathan Lethem’s Amnesia Moon, discontinuities in the characters’ construction of reality are linked to dreams—a blurring of the borderline between physical and imaginative states very much in keep with the work (especially the later books) of Philip K. Dick, whose influence on Lethem is clearly marked in this novel.

Ursula K. Le Guin’s The Lathe of Heaven, a 1971 book that was nominated for both the Hugo and Nebula awards, stands out as an extreme novelistic treatment of dreaming as a world-altering activity. The "effective dreams" of her hero George Orr not only change the future . . . they also change the past. And it is not just his personal past that is altered; the collective past of the planet—and, as it turns out, even the universe—shifts in response to his REM-musings.

Orr first discovered this terrible talent in his teens. At age seventeen he had a dream that his Aunt Ethel had been killed in a car crash in Los Angeles. When he awoke, he learned that not only was his Aunt dead, but that the crash had taken place six weeks before he had the dream! Not every dream is translated so vividly into reality, but his “effective dreams” happen often enough to make Orr wary of the calamities that any given night might leave in its wake.

Orr begins to take prohibited drugs to limit his dreaming or stop it altogether—a rare instance of narcotic abuse to prevent mind-altering states—but this leads to legal problems and his assignment to a government-mandated medical treatment regimen. His doctor, William Haber, is an expert in sleep disorders who has been tinkering with a machine that can influence patients’ dream states. Haber is fascinated with his peculiar patient, but rather than attempt to cure him, the doctor aims to manipulate Orr’s dream power for his own agendas.

Haber’s goals are a mixture of a narcissistic will to power and a zeal for benevolent social engineering. Yet his ability to control the effects of Orr’s dreams is limited at best. The mixed results of his various experiments are sobering lessons in the law of unintended consequences. When Haber tries to use “effective dreams” to create peace on earth, he ends up causing tremendous warfare in outer space. When he attempts to end racial hatred, he also eradicates racial diversity—everybody ends up with gray-colored skin. Le Guin is ingenious in her plot construction in this unfolding series of dreams gone bad. Seldom has any writer done a better job of proving the old adage: “Be careful what you wish for—it might come true.”

Yet Haber is not discouraged by the disastrous side effects of his experiments, and decides that he needs to push ahead to even more ambitious goals—only now he hopes to train his own brain to do the magical dreaming (with a little help from his dream machine). His efforts not only fail, but even threaten to tear apart the physical continuity of experienced reality, and thrust society into a chaotic, nightmarish existence.

Le Guin has added a plausible veneer of science to her story, with various factoids drawn from sleep and dream research brought in to enhance the verisimilitude of what is, by any measure, a book that renounces almost every tenet of realism. Yet the excitement of sci-fi, as I have argued elsewhere, is not derived from its science—which rarely stands up to scrutiny—but rather from its imaginative reconstructions of our perceived reality. And it is here that Le Guin really shines. The premise of this novel, with its soft boundary between dreaming and waking life, allows its author to reach for the most extreme effects. Few writers could handle this freedom as effectively as Le Guin. Yet there is some heavy irony here: since this book is all about the dangers of giving free rein to the constructs of our imagination.